[evlatests] Report from tests of Nov 8

[Rick Perley]

    As mentioned by Ken earlier, we got 1.5 hours of time to continue
system stability and sensitivity tests.   The idea was to do the
fast continuum, many sources experiment at X-band to see if phase spins
and amplitude dropouts are still absent, and both continuum and line
observations at all bands to judge sensitivity. 

    Very little good data were obtained, due to a variety of reasons,
mostly not related to the antennas. 

    From 1.5 minutes of good Xband data, we find:

    1) Antennas 14A, C, and D have near-normal sensitivity. 
The bistable state that was seen on 16D yesterday has migrated
to 14B.  (Jim, Rob -- please tell me that some module was moved
from 16D to 14B!)  The characteristics of this bistable state are
identical to those reported yesterday for 16D:  Two states, separated
by an amplitude ratio of ~1.6 (or 4.4 dB in power ratio).  There are
no amplitudes 'in between' these two.  The sensitivity is poor for both
states.  (This agrees with Ken's assessment of poor amplitudes).
    2) Antennas 16A, B, C, and D all behaved normally, except
that 16A is noisier than the others. 

    We got 6 minutes of data at each of K and Q bands.  From this, we
find that antenna 14 was dead at K-band on all IFs.  No reason
is known.  Ant 16 looked normal at K-band.  At Q-band, ant
14 looked fine.  (There is no Q-band receiver on ant 16). 

    No data were obtained at any other band. 

    It was not possible to judge if the 'dead data at the beginning
of a scan' problem was repaired.  There were only two opportunities
to judge this -- for one, valid data from ant. 16 began at the
beginning of the scan, for the other, about 30 seconds of bad
data for antenna 14 at K-band at the beginning was found. 

    We clearly need to repeat these tests tomorrow or Thursday.